Generation of Ester Plasticizers for High Temperature Ethylene - - PowerPoint PPT Presentation

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Development of New Generation of Ester Plasticizers for High Temperature Ethylene Acrylic Elastomers

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Agenda

• Background on EAM elastomers
• Plasticizer for high-temperature AEM applications
• Goal of the project
• Overview of the experimental plan
• Results and discussion
• Conclusions
• Acknowledgements

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Background on AEM Elastomers

• AEM are used in applications requiring continual service up to 175°C and

intermittent exposure to extremely high temperatures of up to 200 °C

• Lower cost alternatives to FKM and FVQM
• Exhibit improved high temperature resistance over HNBR and ECO
• There are two well known types:

– ACM (Acrylic Co-Monomer) – AEM (Acrylic-Ethylene Monomer)

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Background on AEM Elastomers

• Conventional CB and Silica fillers provide stiffness in AEM compounds but

– Accelerate oxidative degradation – Reduce thermal stability

• DuPont™ developed novel melt-blending technology which allowed reinforcement of AEM

with a dispersion of grafted PA6 droplets

• DuPont™ VMX 5000 elastomers are based on amine cure system
• Result is a strong, heat-resistant elastomer compound with good heat-aging and compression

set properties

• Enhanced performance is due to

– Extensive AEM-PA6 grafting – Absence of filler-filler contacts – Beneficial modification of oxidation profile under diffusion-limited conditions

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Plasticizer for high-temperature AEM applications

• Highly polar AEM elastomers require higher-polarity ester plasticizers to

assure optimal compatibility

• Due to the high post-cure and application temperature requirements few

plasticizer have found utility in demanding AEM applications

• Polar monomeric plasticizer have good low temperature properties but suffer

from higher weight losses during high temperature aging

• Polar high MW plasticizer have good permanence but lack optimal low

temperature flexibility

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Goal of the Project

• To develop new generation of high-performance ester modifiers and help

expand modifier options for the acrylic elastomer market.

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Experimental Plan – Part I

SAMPLES USED IN THIS STUDY

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Testing

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Original Properties – Part I

TegMeR 812 RX-14434 RX-14565 RX-14562 No plasticizer Stress @ 100% Elongation, MPa 2.1 2.0 2.4 2.2 3.0 Stress @ 200% Elongation, MPa 5.6 6.2 7.1 6.6 9.1 Stress @ 300% Elongation, MPa 10.3 11.9 12.6 12.1 15.1 Tensile Ultimate, MPa 13.8 15.6 14.6 14.6 16.2 Elongation @ Break, % 382 367 348 359 318 Hardness Duro A, pts. 60 60 63 58 65 Specific Gravity 1.078 1.078 1.078 1.078 1.079

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Heat Aging – Weight Change, Part I

• 1.6
• 1.4
• 1.2
• 1
• 0.8
• 0.6
• 0.4
• 0.2

0.2 0.4 TegMer 812 RX-14434 RX-14565 RX-14562

Weight Change, % (Normalized)

2 wk @ 190 C 3 wk @ 190 C 4 wk @ 190 C

• Neat AEM polymer exhibited

some weight loss so all of the data were normalized.

• Normalized data helped

elucidate performance differentiation between the 4 samples used in this study

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Heat Aging – Volume Change, Part I

• 1.5
• 1
• 0.5

0.5 1 TegMeR 812 RX-14434 RX-14565 RX-14562

Volume Change, % (Normalized)

2 wk @ 190 C 3 wk @ 190 C 4 wk @ 190 C

• The compounds showing a

weight or volume “gain” are at low enough levels as to be considered equivalent with the control compound, effectively losing no weight or volume due to plasticizer loss

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Heat Aging – Changes in Elongation, Part I

• 20
• 15
• 10
• 5

5 TegMer 812 RX-14434 RX-14565 RX-14562

Elongation Change, % (Normalized)

2 wk @ 190 C 3 wk @ 190 C 4 wk @ 190 C

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Heat Aging – Changes in Tensile Properties, Part I

20 40 60 80 TegMer 812 RX-14434 RX-14565 RX-14562

M100 Change, % (Normalized)

2 wk @ 190 C 3 wk @ 190 C 4 wk @ 190 C

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Heat Aging – Compression Set, Part I

5 10 15 20 25 TegMeR 812 RX-14434 RX-14565 RX-14562 None

Compression Set, %

Original 2 wk @ 190 C 4 wk @ 190 C

70 hrs at 150°C, under constant deformation

22.4 12.0 15.8 14.0 10.2 15.8 23.4 12.9 13.0 14.0 10.8 16.9 14.5 11.2 13.3

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Original Tg, Part I

• As expected, TegMeR 812 is

most efficient at lowering Tg compared to experimental polymeric materials

• All provide good starting Tg
• 39
• 38
• 37
• 36
• 35
• 34
• 33
• 32

TegMeR 812 RX-14434 RX-14565 RX-14562

Original Tg, °C

• 38.46
• 35.68
• 35.64
• 34.58

Ramping -100 to 70 C @ 20 C/min

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Heat Aging – Effect on Low Temperature, Part I

• TegMeR 812, while starting

with the lowest Tg, loses the most performance after aging

• RX-14562 retains the best

performance after aging

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• 38
• 36
• 34
• 32
• 30
• 28

TegMeR 812 RX-14434 RX-14565 RX-14562 None

Tg, before and after aging, °C

Original 2 wk @ 190 C 3 wk @ 190 C 4 wk @ 190 C

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Experimental Plan – Part II

SAMPLES USED IN THIS STUDY

• Based on results from Part I, the

formula was adjusted to increase plasticizer level

• RX-14562, as the best performing

material in Part I, is used as a control

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Original Properties – Part II

RX-14562 RX-14600 RX-14601 RX-14602 RX-14603 No Plasticizer Stress @ 100% Elongation, MPa 2.6 2.7 3.1 2.8 2.7 4.4 Stress @ 200% Elongation, MPa 7.6 7.5 8.5 7.8 7.5 12.4 Stress @ 300% Elongation, MPa 12.8 13.2

• 13.2

12.5

• Tensile Ultimate, MPa

13.0 14.2 13.3 13.9 13.1 16.9 Elongation @ Break, % 305 320 293 316 308 275 Hardness Duro A, pts. 59 58 59 59 57 64 Specific Gravity 1.081 1.082 1.086 1.086 1.085 1.084

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Heat Aging – Weight Change, Part II

• Neat AEM polymer exhibited

some weight loss so all of the data were normalized.

• Normalized data helped

elucidate performance differentiation between the 5 samples used in this study

• 3.5
• 3
• 2.5
• 2
• 1.5
• 1
• 0.5

RX-14562 RX-14600 RX-14601 RX-14602 RX-14603

Weight Change (Normalized), %

2 wk @ 190 C 3 wk @ 190 C 4 wk @ 190 C

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Heat Aging – Changes in Elongation, Part II

• 70
• 60
• 50
• 40
• 30
• 20
• 10

RX-14562 RX-14600 RX-14601 RX-14602 RX-14603 No Plasticizer

Elongation Change, %

2 wk @ 190 C 3 wk @ 190 C 4 wk @ 190 C

• All plasticizers show good

behavior with elongation loss compared to non-plasticized control

• RX-14562 and RX-14600

show best retention of elongation after aging

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Heat Aging – Changes in Tensile Properties, Part II

• 70
• 60
• 50
• 40
• 30
• 20
• 10

RX-14562 RX-14600 RX-14601 RX-14602 RX-14603 No Plasticizer

Tensile Change, %

2 wk @ 190 C 3 wk @ 190 C 4 wk @ 190 C

• All plasticizers show good

behavior with tensile strength loss compared to non- plasticized control

• RX-14562, RX-14600, and

RX-14602 show best retention of tensile strength after aging

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Heat Aging – Compression Set, Part II

70 hrs at 150°C, under constant deformation

5 10 15 20 25 30 RX-14562 RX-14600 RX-14601 RX-14602 RX-14603 No Plasticizer

Compression Set

Originals 2 week aged 4 week aged

• Decrease in compression set

after aging in most cases likely due to increased cross- linking during aging

• Increase in set after aging

likely due to degradation

• RX-14602 overall best initial

compression set and retention after aging

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Heat Aging – Effect on Low Temperature, Part II

• All plasticizers have excellent

initial low temperature properties

• RX-14562 and RX-14602
• ffer best retention of low

temperature properties after heat aging

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• 41
• 39
• 37
• 35
• 33
• 31
• 29
• 27
• 25

RX-14562 RX-14600 RX-14601 RX-14602 RX-14603

Tg by DSC, C

Original 2 wk @ 190 C 3 wk @ 190 C 4 wk @ 190 C

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Conclusions

• Plasticizers tested here offer better

performance than others in different aspects

• Overall, RX-14562, RX-14600, and

RX-14601 offer best maintenance of properties after extreme heat aging

• Adjusting molecular weight and

chemistries of polymeric materials can

• ptimize properties according to

application requirements